The present invention relates to an apparatus for providing interactive program guide (IPG) data for television. In particular, IPG data is provided in a satellite data stream for television decoders which receive both satellite transmissions and local cable television (CATV) transmissions. The IPG data includes global data which describes programming offered by satellite and national cable channels, and network-specific data which describes programming provided by regional cable networks or local terrestrial broadcasters.
The invention has particular applicability to the provision of an IPG for events (e.g., television programs, movies, concerts, sporting events, interactive forums, and the like) available over a satellite or cable television network or off-air channels.
The availability of digital networks for the transmission of games, information services, television programming (including movies and special events), shop at home services, and the like, has vastly increased the number and variety of such services available to consumers. Systems with five hundred or more programming channels have been in operation. One challenge that has emerged in the development and design of such systems is how to keep consumers informed as to the scheduling of the many different events that are offered.
A logical solution to the problem of providing an accurate, up-to-date guide for a large number of events is to provide the guide via an electronic medium. Program guides can now be downloaded to a subscriber terminal, such as a "set top box" or "integrated receiver-decoder" (IRD) connected to a subscriber's television. One stumbling block in implementing such an electronic program guide is the amount of bandwidth required to carry the large amount of scheduling information over a communication channel.
Another obstacle is the amount of memory required to store scheduling data for a week or more within the set top box. Such random access memory (RAM) is relatively expensive. This conflicts with the requirement that a consumer set top box be a relatively inexpensive item.
Another problem is the provision of the schedule information in a timely manner. Subscribers would grow impatient if the response time for providing scheduling information in answer to a query for such information for a particular time slot takes too long. In an ideal system, a subscriber would receive an immediate answer to a request for scheduling information pertaining to a particular channel and/or time period. After obtaining scheduling information, a subscriber may desire to have further details about a particular program. Again, it would be inconvenient to wait for more than a few seconds to obtain descriptive information about a program. Ideally, the information should be provided almost instantaneously after being requested.
A further problem is that television and other programming service signals may be delivered via different communication networks or plants. For example, a user may now receive television signals via a cable television network or a via a direct satellite link to the user's home. Integrated receiver decoders (IRDs) may include both a satellite tuner/demodulator as well as a CATV tuner/demodulator. Television signals which are transmitted by satellite can generally be received nationwide, for example, in the continental United States.
Thus, such signals are typically reserved for programming which is of interest to all or most recipients, and do not include programming which is only of interest to specific geographical regions. For example, satellite broadcasts may include network television programs and national news broadcasts, but will not include local news programs, local advertising or local interest "infomercial" programming (such as video "homes for sale" programs), or local access programming. Local access programming refers to programming time which CATV operators may be required to allot to educational, civic and other non-profit organizations.
Furthermore, programming may also be transmitted by terrestrial broadcast. Different users may receive different terrestrial broadcasts depending on factors such as topology and antenna size, for example. Thus, the number and identity of users who receive a specific terrestrial broadcast is not well defined. The concept of a terrestrial broadcast network can nevertheless be defined generally, if not exactly, in terms of the user's location. In contrast, the number and identity of users who can receive a cable television signal is defined by the cable plant itself, e.g., the location of the cable.
Terrestrial broadcast and CATV networks provide both global interest programming, such as network television programs and national news broadcasts, as well as local interest programs. In the United States, it is estimated that a few hundred national programming sources are available to CATV systems. These sources include satellite sources which are transmitted to CATV headends, national cable channels, and affiliated source groups or network programming, e.g., the ABC and CBS networks.
Local or regional programming sources are believed to number in the thousands, but this programming is available to only a small number of CATV systems. These sources include independent local sources, and affiliates of the major national program networks. A typical CATV channel line-up consists of a number of local sources (e.g., ten to twenty), with the remainder (e.g., fifty to sixty) being a subset of the national sources. Thus, about two thirds of the CATV channels are global interest (e.g., non-network-specific) programming, and one third are local interest (e.g., network-specific) programming.
Accordingly, there is a need for a system to provide scheduling information for both global and local programming. The system should seamlessly integrate the scheduling information for programming which is provided over two or more communication networks. The system should be compatible with IRDs having both satellite and CATV tuner/demodulators. The system should allow the IRD to filter out local scheduling information which does not pertain to the network to which the IRD is associated, as well as filtering out global scheduling information for programs that do not correspond to the set of channels available to the individual IRD (as defined by its "channel map"). The system should allow the communication of scheduling information for television programming as well as other types of data, such as computer programs and games, and stock or weather data, for example.
The interactive program guide should be economical in terms of both communication bandwidth and cost. The guide should respond to user inquiries on an instantaneous or near instantaneous basis. The guide should be compatible with relatively inexpensive set top boxes, and should adapt to the amount of RAM available in a particular set top box.
The present invention provides a method and apparatus for implementing an interactive guide to events having the above and other advantages.